In 1971, geologists discovered a huge underground deposit of natural gas on this site. And while excavating, a whole drilling rig fell into an underground cavern. Natural gas started coming up from the hole. To prevent gasses from escaping, it was set alight and it continues to burn even today. The crater measures roughly 60 meters in diameter and 20 meters deep and is located in Turkmenistan.

Hat tip to RFE/RL's Grant Podelco, who quips, "Everyone knows Turkmenistan is a pretty oppressive place in which to live, but who knew you could find the Gates of Hell there?"